Insecticide



Patented Apr. 25,1944

HQSEC'I'ICIDE Julius Hyman, Chicago, 111., assignor to Velsicol Corporation, Chicago, 111., a corporation of lilinois No Drawing. Application May 25, 1942,

- Serial No. 444,397

6Claims.

This is a continuation-in-part of my co-pending application Serial No. 385,674, filed November 14, 1940.

This invention relates to improvements in insecticides.

Among the objects of the invention is the preparation of insecticidal substances from rawma-' terials found abundantly in the United States, which are relatively inexpensive, said insecticidal substances being relatively non-toxic to man and warm-blooded animals, but being decidedly toxic and repellent to a great variety of insects and allied forms of life, said insecticides also showing great resistance to deterioration on storage.

This invention contemplates the use of alkyl substituted derivatives of naphthalene, especially the methyl substituted derivatives thereof, as insect toxicants and repellents. By substituted derivatives of naphthalene is meant the replacement of one or more hydrogens in naphthalene by a like number of alkyl, and specifically methyl, groups. The number of substituting groups may be one or more, These materials are found naturally occurring as minor components of mineral oils, and maybe isolated in small amounts from cracked fuel oils used commercially, The proportion of such compounds present in the aforementioned oils, however, is so small that these oils in themselves possess no appreciable insecticidal value over oils which are free from naphthalene substitution products.

Alkyl substituted naphthalenes, and especially methyl substituted naphthalenes, are present in moderate quantities in certain coal tar distillates,

such as creosote oils, and in certain heavy petro leum fractions resulting from the dehydrogenation of aliphatic or hydroaromatic hydrocarbons, or the polymerization and consequent dehydrogenation of unsaturated hydrocarbons. For example, the distillate formed in the ordinary hightemperature coking operation contains a great variety of higher aromatics, along with sulfur compounds, tar acids, and nitrogen bases. Various methylated naphthalenes can be separated from this oil. However, the separation in this instance is not simple, because of the difiiculty of freeing the hydrocarbons from the aforementioned unpleasant-adored sulfur compounds. Furthermore, the yields of alkylated naphthalenes produced from coal tar distillation is not particularly great.

erately high pressures, in the presence of hydrogen gas and aluminaceous catalysts, there is produced a small proportion of heavier oils which contain alkylated naphthalenes. Another method for producing the monoand poly-methylated naphthalenes from petroleum is by means of high temperature cracking of petroleum oils at relatively low pressures. It is possible to produce from such source oils very rich in alkylated naphthalenes, and which may be freed from all but small percentages of unpleasant sulfur compounds, tar acids, and nitrogen bases by further refining.

It has in the past been assumed that the hydrocarbons in the aforementioned alkylatednaphthalene containing oils were insecticidally inactive. were not purified or freed from their unpleasant sulfur, oxygen, and nitrogen concomitants (which were considered as possessing whatever insecticidal activity existed in the oils) whenever such oils were used in the preparation of sheep dips, wood preservatives, weed killers, etc. These oils, as heretofore used, have, because of their unpleasant (and oft-times toxic or irritating) concomitants, been unsuitable for use in household and dairy sprays and in agricultural insecticides. Furthermore, such unrefined oils may contain higher boiling anthracene and phenanthrene derivatives possessing carcinogenic properties, inasmuch as cancer-producing hydrocarbons have been isolated therefrom.

For this reason, such hydrocarbons- I have discovered that the alkyl substituted naphthalenes, and especially the methyl substituted naphthalenes possess in themselves a comparatively high degree of toxicity toward insects,

arachnids, worms, and the like, combined with A further example of the production of alkyl- I the property of insect repellency. I find that insecticides-"containing refined oils, rich in alkylated naphthalenes, low in unsaturated hydrocarbons, and sensibly free of unpleasant sulfur compounds, tar acids and nitrogen bases make excellent household and dairy sprays and agricultural insecticides. Insecticides of various compositions containing the aforementioned refined alkylated naphthalenes' have been tested against flies, cockroaches, bedbugs, mosquitoes, flour beetles, aphids, red spiders, and a number of other insect pests, with excellent results. As examples of such activity the following tests are reported. Wherever feasible, in these tests, insecticides containing the refined alkyl substituted naphthalene oils have been compared with the Oflicial Test Insecticide. This insecticide, which is distributed by the National Association of Insecticide and Disinfectant Manufacturers, Inc., is generally referred to as the OTI.

Ensues: 1

Two liquids, A and B, were tested against the CT! on the common housefly according to the Pest-Grady large group method. (Soap Blue Book... 1940.) The Feet-Grady test is generally considered as standard in testing the. action of insecticides on houseflies. Material A consisted exclusively of refined hydrocarbons, which mixture boiled between about 450 and 500 1'. (Engler) and contained upward of 70 per cent monoand di-methyl naphthalenes, the remaining hydrocarbons consisting of various higher boiling alka'nes, alkenes and aromatics. Material B consisted exclusively of reilned hydrocarbons, which mixture boiled between about 500 and 550 F.

(Engler) and contained upward of 70 per cent polyalkylated naphthalenes. A typical test is shown below.

Table I Percentage P b Material kno own G dy mm 24110111: mung Minutes A 2 97 +55 B 2 96 +54 T1. 2% I 42 v 0 Emma-2 The alkylated naphthalene materials, A and 3, proved themselves extremely toxic toward the common housefly when the test liquids were used in extremely fine suspension in air (the so-called aerosols). The following results are typical:

The following results were obtained with Peet- Grady tests on the common housefly when material B was admixed with other toxicants and mineral oil diluents (Percentages set forth in the formulations are in each instance by volume unless otherwise in dicated.)

Table III .322%; Per cent Peet- Formulation down mortality Grady time 24 hours rating Minutes 25% material B 0.1;: o derris resins (rotenone) (by 2% fit'ifi'fi'ii sigma till) 3% 4 cyana' 72.875% Mineral see! 011 2'7 Lethane 384 50% material B 3 3 1 4 its? tt""'(a7i""aaisiaias' rum con 40 hm 5m B 3 7a +25. 4 whi 2 ans 40 material B- 3 63 +10. 4 58 Deobase 25 a material 13 2.507 yrethrum (/1 concentrate). 77. 6 72.50% mineral seal oil.- OTI. 62 6 Average 12 tests Exams 4 In these tests on the houseflm'material A (in admixturewith pyrethrum concentrate and refined mineral oil) was compared with the OTL Thisseries oftestaaswellasthoseshownin Example No. 3, indicates a synergistic action between the alkylated naphthalenes and other toxicants such as pyrethrum extract, rotenone, or-

ganic thiocyanates. etc., inasmuch as the mortality found is greater than might have been anticipated if the action of the constituents had been simply additive.

Emu: 5

The following experiment indicates the repellency of materials A and B compared with two popular dairysprays known for their repellent qualities. The test equipment was the Hoskins Olfactometer (Hoskin, W. M., and Craig, 1%., Jour. Econ. Entom. 28:1029-1036 (1934) and the ratio given is that of the proportion of houseflies on the test area to those ofl the test area. The repellent properties of materials A and B are very evident.

The fumigating power of the vapors of the mixed methylated naphthalenes (as emitted from material A) was compared with that of fumigants known to be efiective. The tests were carried out at a temperature of about F. The test insect was a confused flour beetle. Typical results as shown herewith.

Exams: "I

' and others. In certain of these tests more highly concentrated methylated naphthalenes were tested. In other tests, the refined alkylated naphthalenes were admixed with various natural and synthetic insecticides, such as pyrethrum and rotenone, and their allied resins, compounds and extracts; organic thiocyanates and numerous other synthetic insecticides now available. In general such mixtures possessed unexpectedly high toxicities, indicating that the alkylated naphthalenes acted synergistically, or possibly as activators, for the other toxicants. Certain ex 'periments were carried out in which my materials were used in emulsion form, where the emulsifying agents were such diverse materials as bentonite, sulfonates, organic sulfates and similai' wetting agents, ethyl cellulose, etc. Still other tests were performed in which my materials were admixed with dry powders and dusts, such as talc, precipitated calcium carbonate, diatomaceous earth, lime, etc. From these various tests, using my materials, .by the methods which "seemed most appropriate in combatting the insect pest in question, and with such admixtures as proved best from the standpoints of cost, avail- -,ability, and applicability, the alkylated naphthalenes have proved themselves to be very potent insecticides toward an extremely wide variety of insects. I have, in fact, not encountered any insect which appears immune to the tbxic effects 01' the alkylated naphthalenes herein claimed, provided the proper method of application is used.

The aforementioned examples are given to illustrate the value of my invention. They are in no way meant as limiting its scope.

The term, refined, as herein used, means purification and concentration through such measures as careful fractional distillation (ordinary and/or azeotropic, vacuum, steam) and/or crystallization, acid treatment to aid in the removal of objectionable sulfur and nitrogen compounds, siliceous catalyst treatment to polymerize objectionable and irritating unsaturates (which may then be removed by fractionation), caustic washing to remove tar acids and certain sulfur compounds, solvent'extraction, treatment by solid absorbents, etc. The purpose of the refining steps are the removal of objectionable concomitents of the alkylated naphthalene hydrocarbon oil fractions, the presence of which would thwart the general use of these oils in household, dairy, industrial and agricultural applications. All this is not to say that the refined products, use of which is herein contemplated, cannot be admixed with certain base oils and fuel oils of cer tain desired characteristics in order to utilize the toxicity and repellency of my products to the best advantage.

My experience indicates that not less than: 10% by volume of alkylated naphthalene rich oil (containing at least 70% by volume of alkylated naphthalene) must be present in the oil phase of a prepared insecticide in order for said alkylated naphthalene to exhibit insecticidal activity.

relatively inexpensive. Investigation indicates that they can be marketed at prices calculated to offer the consumer more insecticidal potency and repellency per unit cost than any other toxicant or re llent currently marketed.

Chemical analysis of the alkylated naphthalenes derived from the pyrolysis of petroleum and coal indicates that they consist chiefly of monoand poly-methyl naphthalenes. These substituted naphthalenes boil in a range from about 465 F. to about 625 F. Concomitant hydrocarbons may lower somewhat the Engler boiling ranges of the mixtures, while slight decomposition may produce small percentages of residue on distillation. Inasmuch as many methylated naphthalenes have never been isolated or described, the identification and evaluation of various isomers involves considerable difilculty. Nevertheless, insect toxicity tests have been run on carefully purified fractions of all lated naphthalenes. These tests have corroborated the evidence obtained with the less carefully refined commercial alkylated-naphthalene-rich oils.

Skin sensitivity tests of the alkylated naphthalenes on human subjects have revealed no allergic manifestations. Chemical experimentation on dogs, cows and rats indicates that the alkylated naphthalenes produce mild skin irritation and internal symptoms, these being of the same general order of magnitude as those produced by deodorized commercial kerosene, in equal weight dosage. The alkylated naphthalenes appear to exert a decided repellent action on rodents, and their commercial use in this connection is indicated.

Certain of the alkylated naphthalenes, whose use is herein contemplated, are solid at ordinary temperatures. They are found in the crude products resulting from the thermal and catalytic cracking and/or polymerization of hydrocarbons, and may be isolated by exceedingly careful refining, which may also include separations by freezing, or selective extraction or absorption. Such solid alkylated naphthalenes may be utilized either as such (in the solid form) or may be dissolved or admixed with other toxicants or with solid or liquid diluents, and utilized as would be best suited for the problem at hand. Inasmuch as the experiments which I have caused to be performed have shown that the alkylated naphthalenes possess considerable phytotoxicity, care must be used when eradicating agricultural pests, so as not to harm foliage or plant life unduly. Experience indicates that, for agricultural purposes, it is best to use the alkylated-naphthalenerich hydrocarbons as dusts, water emulsions or aerosols. With respect to the water emulsions, effective results are only obtained when the alkylated naphthalene is associated with a synergist.

I claim as my invention:

1. An insecticide comprising refined inactive carrier oils containing, as an active ingredient, a methyl substituted naphthalene.

2. A non-aqueousinsecticide containing, as an active ingredient, a refined hydrocarbon oil fraction, said fraction comprising at least '70 per cent by volume of methylated naphthalene.

3. An insecticide containing as an active ingredient methylated naphthalene in synergistic and rotenone.

association withenother active insect toxicant seiected mm the zroup consisting of pmthrum selected from the group consisting of pyrethrum androtenone,

- 5. An insecticidal material comprising dust im. 4. An insecticide containing as an active inpregnated withamethyl mbstitutednaphthalene. crediente. refined hydrocarbon on fraction rich 5 6. An insecticidaimateriai comprising a nonin methyl substituted naphthalene in synergistic aqueous carrier and methylated naphthalene. association with another active insect toxicant JULIUS HYMAN. 

